boolean isChecksumError() {
if (header.getProtection() == Header.MPEG_PROTECTION_CRC) {
if (header.getLayer() == Header.MPEG_LAYER_3) {
CRC16 crc16 = new CRC16();
crc16.update(bytes[2]);
crc16.update(bytes[3]);
// skip crc bytes 4+5
int sideInfoSize = header.getSideInfoSize();
for (int i = 0; i < sideInfoSize; i++) {
crc16.update(bytes[6 + i]);
}
int crc = ((bytes[4] & 0xFF) << 8) | (bytes[5] & 0xFF);
return crc != crc16.getValue();
}
}
return false;
}
public ReadPacket(byte[] readPacket) {
this.command = readPacket[OFFSET_CMD];
this.data = Arrays.copyOfRange(readPacket, OFFSET_DATA, readPacket.length - CRC_LEN);
this.crc = Arrays.copyOfRange(readPacket, readPacket.length - CRC_LEN, readPacket.length);
this.crc_calc = CRC16.calculate(readPacket, 0, readPacket.length - 2);
if (!Arrays.equals(this.crc, this.crc_calc)) {
throw new CRCFailRuntimeException(
"CRC check failed: "
+ Utils.bytesToHex(this.crc)
+ " vs "
+ Utils.bytesToHex(this.crc_calc));
}
}
public boolean parse(byte[] data, int ofs) {
final int origOfs = ofs;
int fh32 =
(data[ofs] << 24)
| ((data[ofs + 1] & 0xFF) << 16)
| ((data[ofs + 2] & 0xFF) << 8)
| (data[ofs + 3] & 0xFF);
FrameHeader fh = new FrameHeader(fh32);
ofs += 4 + fh.getSideInfoSize();
boolean xingTag =
(data[ofs] == 0x58) // 'Xing'
&& (data[ofs + 1] == 0x69)
&& (data[ofs + 2] == 0x6E)
&& (data[ofs + 3] == 0x67);
boolean infoTag =
(data[ofs] == 0x49) // 'Info'
&& (data[ofs + 1] == 0x6E)
&& (data[ofs + 2] == 0x66)
&& (data[ofs + 3] == 0x6F);
if (!xingTag && !infoTag) {
return false;
}
ofs += 4;
this.xingTag = xingTag;
this.infoTag = infoTag;
this.frameSize = fh.getFrameSize();
System.arraycopy(data, origOfs, bb, 0, frameSize);
int flags = data[ofs + 3] & 0xFF;
ofs += 4;
if ((flags & 0x01) != 0) ofs += 4; // skip frame count
if ((flags & 0x02) != 0) ofs += 4; // skip byte count
if ((flags & 0x04) != 0) ofs += 100; // skip seek table
if ((flags & 0x08) != 0) ofs += 4; // skip VBR scale
int tagEndOfs = ofs + 0x24;
int crc = 0;
for (int i = origOfs; i < tagEndOfs - 2; i++) {
crc = CRC16.updateLAME(crc, data[i] & 0xFF);
}
this.lameTag =
(data[ofs] == 0x4C)
&& (data[ofs + 1] == 0x41)
&& (data[ofs + 2] == 0x4D)
&& (data[ofs + 3] == 0x45);
if (!this.lameTag) {
this.lameTag =
(data[ofs] == 0x47)
&& (data[ofs + 1] == 0x4F)
&& (data[ofs + 2] == 0x47)
&& (data[ofs + 3] == 0x4F);
}
this.lameTag |=
((((data[tagEndOfs - 2] << 8) | (data[tagEndOfs - 1] & 0xFF)) ^ crc) & 0xFFFF) == 0;
if (this.lameTag) {
lameTagOfs = ofs - origOfs - 4;
}
ofs += 0x15;
int t = data[ofs + 1] & 0xFF;
encDelay = ((data[ofs] & 0xFF) << 4) | (t >>> 4);
encPadding = ((t & 0x0F) << 8) | (data[ofs + 2] & 0xFF);
if (!this.lameTag) {
if (encDelay > 2880 || encPadding > 2304) {
encDelay = 576;
encPadding = 0;
}
}
return true;
}
public static int createHeaderFrame(
FrameHeader toBeSimilar,
boolean vbr,
float kbps,
int frameCount,
int musicBytes,
int vbrScale,
byte[] seektable,
int encDelay,
int encPadding,
XingInfoLameTagFrame srcTag,
byte[] dest,
final int dofs,
final int maskATH) {
int fh32 = toBeSimilar.getHeader32() | 0x00010000; // disable CRC if any
int frameSize = 0;
int tagOffset = 0;
{ // calculate optimal header frame size
FrameHeader tmp = new FrameHeader();
float minDist = 9999;
for (int i = 1; i < 15; i++) {
int th32 = (fh32 & 0xFFFF0FFF) | (i << 12);
tmp.setHeader32(th32);
if (tmp.getFrameSize() >= 0xC0) {
int ikbps = tmp.getBitrateKBPS();
float dist = Math.abs(kbps - ikbps);
if (dist < minDist) {
minDist = dist;
fh32 = th32;
frameSize = tmp.getFrameSize();
tagOffset = tmp.getSideInfoSize() + 4;
}
}
}
}
tagOffset += dofs;
Arrays.fill(dest, dofs, dofs + frameSize, (byte) 0);
dest[dofs] = (byte) (fh32 >>> 24);
dest[dofs + 1] = (byte) (fh32 >>> 16);
dest[dofs + 2] = (byte) (fh32 >>> 8);
dest[dofs + 3] = (byte) fh32;
if (vbr) {
dest[tagOffset++] = (byte) 0x58; // X
dest[tagOffset++] = (byte) 0x69; // i
dest[tagOffset++] = (byte) 0x6E; // n
dest[tagOffset++] = (byte) 0x67; // g
} else {
dest[tagOffset++] = (byte) 0x49; // I
dest[tagOffset++] = (byte) 0x6E; // n
dest[tagOffset++] = (byte) 0x66; // f
dest[tagOffset++] = (byte) 0x6F; // o
}
dest[tagOffset++] = 0;
dest[tagOffset++] = 0;
dest[tagOffset++] = 0;
dest[tagOffset++] = 0x0F;
dest[tagOffset++] = (byte) (frameCount >>> 24);
dest[tagOffset++] = (byte) (frameCount >>> 16);
dest[tagOffset++] = (byte) (frameCount >>> 8);
dest[tagOffset++] = (byte) frameCount;
int temp = frameSize + musicBytes;
dest[tagOffset++] = (byte) (temp >>> 24);
dest[tagOffset++] = (byte) (temp >>> 16);
dest[tagOffset++] = (byte) (temp >>> 8);
dest[tagOffset++] = (byte) temp;
System.arraycopy(seektable, 0, dest, tagOffset, 100);
tagOffset += 100;
dest[tagOffset++] = (byte) (vbrScale >>> 24);
dest[tagOffset++] = (byte) (vbrScale >>> 16);
dest[tagOffset++] = (byte) (vbrScale >>> 8);
dest[tagOffset++] = (byte) vbrScale;
if (srcTag != null && srcTag.isValid() && srcTag.lameTagPresent()) {
System.arraycopy(srcTag.bb, srcTag.lameTagOfs, dest, tagOffset - 4, 40);
tagOffset += 4;
// delete LAME's replaygain tag
for (int i = 0; i < 8; i++) {
dest[tagOffset + 0x07 + i] = 0;
}
// deleting no-gap flags ...
dest[tagOffset + 0x0F] &= maskATH;
} else {
dest[tagOffset++] = (byte) 0x4C; // L
dest[tagOffset++] = (byte) 0x41; // A
dest[tagOffset++] = (byte) 0x4D; // M
dest[tagOffset++] = (byte) 0x45; // E
}
encDelay = Math.max(0, Math.min(encDelay, 4095));
encPadding = Math.max(0, Math.min(encPadding, 4095));
// write encDelay / encPadding ...
dest[tagOffset + 0x11] = (byte) (encDelay >>> 4);
dest[tagOffset + 0x12] = (byte) ((encDelay & 0xF) << 4 | (encPadding >>> 8));
dest[tagOffset + 0x13] = (byte) encPadding;
temp = frameSize + musicBytes;
dest[tagOffset + 0x18] = (byte) (temp >>> 24);
dest[tagOffset + 0x19] = (byte) (temp >>> 16);
dest[tagOffset + 0x1A] = (byte) (temp >>> 8);
dest[tagOffset + 0x1B] = (byte) temp;
int crc = 0;
for (int i = 0; i < 190; i++) {
crc = CRC16.updateLAME(crc, dest[dofs + i] & 0xFF);
}
dest[tagOffset + 0x1E] = (byte) (crc >>> 8);
dest[tagOffset + 0x1F] = (byte) crc;
return frameSize;
}
